1. Field of the Invention
The present invention relates to a method of producing a foam base material product with a securing device for providing superior and simple assembly.
2. Description of the Related Art
Reference is made to U.S. Pat. Nos. 4,101,617, 4,873,045 and 4,968,474 as related art.
As shown in FIGS. 9 and 10, an instrument panel 8 has a complicated shape that requires many different steps to manufacture. For this, the panel 8 is formed from a composite sheet 80 consisting of a surface layer 81 and a foam base layer 82. The panel 8 is fixed to an auto body with a securing device 7 such as a clip, boss, bolt, etc.
Prior to fixing the above securing device 7 to the back surface of the panel, i.e., to foam base layer 82, a securing device seat 71 is bonded to the foam base layer 82 through vibration deposition, hot-melt, etc. Then an engagement piece 712 of a clip 72 is engaged with an engagement recess 711 of the seat 71.
When fixing the panel 8 to the auto body, a top end protrusion 722 of the clip 72 is engaged with a securing recess provided in the auto body.
The aforementioned instrument panel, however, has the following problem. Since the securing device 7 is bonded using a bond means such as vibration deposition, adhesion, etc., the bonding position is likely to be inconsistent, resulting in troublesome operation and poor assembly.
Fixing the panel 8 to the body deteriorates the accuracy of assembly. The bonded securing device 7 is likely to be damaged by shock due to insufficient strength of the bond. Further, assembly of panel 8 to the auto body requires a long time period to complete.
It is desirable that the securing device 7 can be directly fixed to the back of the instrument panel 8, i.e., foam base layer 82. The securing device 7, however, cannot be directly deposition bonded to the base layer 82 by adhesion.